Multi-purpose weed suppressant and plant growth enhancement device

ABSTRACT

An agricultural growth control device ( 2 ) includes an organic, biodegradable, layer ( 6 ) and an impermeable sheet ( 4 ) affixed to the underside of the organic layer to form a unitary ground collar ( 8 ). The ground collar defines at least one hole ( 10 ) to allow growth of a plant (P) therethrough while suppressing the growth of weeds or grass around the plant. The impermeable sheet is preferably formed from a slurry of cellulosic fiber and water and the organic layer is preferably formed from a slurry of fiber, water and finely chopped organic material, such as straw, manure, leaves or almond wood chips. The fiber and chopped organic material provide a semi-rigid mulch cover for suppressing weeds around the plant. The mulch cover is easily positioned around the plant and, once it is so disposed, will be relatively impervious to severe weather, such as heavy rainfall and winds. The chopped organic material, particularly almond wood chips, enhance the appearance of the mulch cover.

This application is a continuation of Ser. No. 08/646172, filed May 7,1996, now abandoned, which is a division of Ser. No. 08/538693, filedOct. 3, 1995, now abandoned.

BACKGROUND OF THE INVENTION

This invention relates to plants generally, and more specifically to amulti-purpose device for suppressing weeds and enhancing plant growth.

Crops, plants, trees and vegetables growing on commercial farms or inmunicipal and household gardens must constantly battle weeds forsurvival. Undesired growth of weeds, grass and the like in the regionimmediately adjacent the stems or trunks of plants and trees is bothunsightly and difficult to control because ordinary mowers and othercutting devices cannot efficiently cut such undesired growth.

Although there are existing chemicals that can be used to preferentiallykill the weeds, these chemicals are typically harmful to theenvironment. Other methods of suppressing weeds, such as positioningplastic or cloth weed guards as barriers around plants and crops, areexpensive and they also can be harmful to the environment becauseplastic and cloth are generally not biodegradable. Less harmful orbiodegradable weed barriers, such as newspaper or cardboard, aretypically swept away by the wind or a heavy rainfall.

Another problem faced by farmers is disposing of the waste byproductsthat result from growing food products on farms. For example, almondgrowers must destroy massive quantities of wood pruned from their treesevery year. Burning the wood is harmful to the environment andcogeneration plants have become too expensive. What is needed is arelatively inexpensive method of discarding farm waste products, such asalmond wood chips, without harming the environment.

SUMMARY OF THE INVENTION

The present invention is directed to an agricultural growth controldevice for suppressing weeds and enhancing plant growth. The growthcontrol device will effectively inhibit the growth of ground cover, suchas weeds and grass, around the base of plants, trees or othervegetation. In addition, the device will enhance the growth of the plantby collecting rainwater and gradually introducing nutrients orfertilizers into the soil around the plant. The device of the presentinvention also provides a relatively inexpensive method of discardingfarm waste products, such as almond wood chips, without harming theenvironment.

The agricultural growth control device includes an impermeable sheetcontaining at least one hole and an organic, biodegradable layer affixedto the top side of the impermeable sheet. The growth control device hasat least one hole cut through the impermeable sheet to allow growth of aplant therethrough while suppressing the growth of weeds or grass aroundthe hole. The impermeable sheet preferably formed from a slurry ofcellulosic fiber, such as newspaper or cardboard, and water. Theorganic/acetic top layer is preferably formed from a slurry of paper,water and finely chopped organic material, such as straw, manure, leavesor almond wood chips.

One of the advantages of the present invention is that the fiber andchopped organic material provide a semi-rigid mulch cover forsuppressing weeds around the plant. The mulch cover is easily positionedaround the plant and, once it is so disposed, will be relativelyimpervious to severe weather, such as heavy rainfall and winds. Thechopped organic material, particularly almond wood chips, enhance theappearance of the mulch cover. In addition, the entire device willeventually (within a few months) decompose into the soil, therebyproviding an easy, non-harmful method of disposing of these wood chips.

The present invention also provides a unique method for manufacturingthe agricultural growth control device. The impermeable sheet is formedby grinding a secondary cellulosic fiber, such as paper, into water toform a slurry. The paper slurry is then drained, rolled and pressed on abelt to remove as much of the moisture as possible, forming a semi-rigidfirst layer. The organic layer is formed by mixing the chopped up almondwood chips (or other organic material) with paper into a second slurry.This second slurry is applied to the first layer and the combination ispressed to eliminate moisture and then baked to create the finalsemi-rigid product. The paper helps the wood chips stick together andhelps the second layer stick to the first layer.

The semi-rigid product can be individually tailored for large farms orfor individual trees, plants or vegetables. For example, a square orrectangular piece with a relief or hole in the center may be placed ontothe ground over a seed so that a plant can grow through the mulch cover,but weeds cannot. In addition, a curvature can be formed in the mulchcover to cause rainwater to flow towards the plant, rather than into thesoil, thereby conserving the water. The impermeable sheet may alsoinclude soil nutrients, chemical fertilizers or other water solublesoil-conditioning agents imbedded therein. These agents will graduallyseep into the adjacent soil to enhance the growth of the plant.

In a specific configuration, the almond wood chips and fiber are choppedinto fine pieces by a chip cutter before they are mixed with the waterto form a slurry. The chip cutter comprises an axle shaft connected to acylindrical base assembly made of a plurality of pipes extending throughcircumferentially spaced holes in annular spacer disks. A plurality ofcutting blades are slidably and rotatably mounted to the pipes. Thecutting blades are mounted between the spacer disks along each pipe andextend in both the circumferential and longitudinal directions. The axleshaft is coupled to a motor for rotating the base assembly and thecutting blades around the longitudinal axis. The organic material and/ornewspaper can then be fed into the rotating blades and cut into finelychopped pieces.

The above is a brief description of some deficiencies in the prior artand advantages of the present invention. Other features, advantages andembodiments of the invention will be apparent to those skilled in theart from the following description, accompanying drawings and appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a perspective view of an agricultural growth control devicemanufactured according to the principles of the present invention,illustrating one potential use for the device;

FIG. 2 is cross-sectional view of the agricultural growth control devicetaken along lines 2—2 in FIG. 1;

FIG. 3 is a schematic view of a method of manufacturing an agriculturalgrowth control device according to the invention;

FIGS. 4A-4C are schematic views of alternative embodiments of theagricultural growth control device of FIG. 1;

FIG. 5 is a partial side cut-a-way view of a chip cutter according tothe principles of the present invention;

FIG. 6 is a side cross-sectional view of a portion of the chip cutterFIG. 5 connected to a multiple belt pulley for rotating the chip cutter;

FIG. 7 is a front sectional view of the chip cutter of FIG. 5; and

FIGS. 8-10 illustrate one of the cutting assemblies of the chip cutterof FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings in detail, wherein like numerals indicate likeelements, an agricultural growth control device 2 is shown constructedaccording to the principles of the present invention. Agriculturalgrowth control device 2 generally includes an impermeable sheet 4 bondedto the underside of a biodegradable, organic top layer 6 to thereby forma unitary ground collar 8 for disposition around the base of a tree,bush, plant or other vegetation.

Referring to FIG. 2, impermeable sheet 4 and organic layer 6 eachinclude an opening aligned with each other to form a central hole 10through collar 8. Hole 10 allows a plant to grow through device 2 andpreferably has a diameter of ½ to 3 inches. Of course, hole 10 may belarger if, for example, ground collar 8 is disposed around large treesor bushes. Organic layer 6 preferably has a concave upper surface 12that slopes downward towards hole 10. Likewise, the impermeable sheet 4has a generally concave shape and a relatively planar lower surface 14so that the thickness of the central portion of collar 8 issubstantially less than the thickness of the perimetrical edge of collar8. Concave surface 12 of biodegradable sheet 6 and the concave shape ofmat 4 allow rainwater to flow radially inward toward central hole 10 andplant P. This facilitates plant growth in dry regions because the plantis able to receive water that otherwise may have been absorbed into theground surrounding plant P.

As apparent from FIG. 1, collar 8 is formed with a slit 14 extendingfrom an outer surface 16 of collar 8 to central hole 10 so that collar 8can be easily wrapped around the stem of a plant P. Collar 8 precludesundesired vegetation, such as weeds or grass, from growing in the regionimmediately adjacent plant P. To that end, collar 8 will preferably havea diameter sufficient to block or at least impede the growth ofsurrounding weeds or grass that will substantially interfere with thegrowth of plant. This diameter will, of course, vary depending on manyvariables, such as the surrounding vegetation, the type of plant or thehorizontal extent of the plant's roots under the ground.

Impermeable sheet 4 can be of any thickness, but is preferably in therange of ⅛ to 2 inches. The sheet 4 will comprise at least 50% by volumecellulosic fibers and preferably at least 75% by volume cellulosicfibers. Typical suitable cellulosic fibers include secondary fibers,such as paper, disposable diapers, cardboard, newspaper etc. Primaryfibers, such as trees, sisal, jute and the like, may also be utilizedfor impermeable sheet 4. As discussed in more detail below, sheet 4 ispreferably formed by mixing the fibers with water in a slurry andpressing and heating the slurry to form a semi-rigid mat. Othermaterials, such as seeds, chemical fertilizer, soil nutrients, such asnitrogen, phosphorus and potassium, or other water solublesoil-conditioning agents, can be imbedded into sheet 4. These materialsmay be imbedded into the impermeable sheet after it has been dried andpressed or they may be added to the fiber slurry during the manufactureof agricultural growth control device 2.

Biodegradable, organic layer 6 may be formed from a variety of materialsthat will enhance the appearance of device 2 and will eventually (withina few weeks to a few months) decompose into the soil. In the preferredembodiment, organic layer will comprise waste byproducts, such as straw,manure, leaves or almond wood chips, that result from growing foodproducts on farms. These waste byproducts are typically difficult andoften expensive to discard.

In a specific embodiment, organic layer will comprise at least 40%,preferably at least 60%, by volume of finely chopped almond wood chips.In addition, organic layer will comprise at least 20% of a paperproduct, such as newspaper or cardboard. The wood chips and the paper(which act as a binder) are mixed together with water in a slurry andthen dried to form a rigid product, as discussed in detail below. Thealmond wood chips provide an aesthetic appearance to collar 8 and thepaper helps the wood chips stick together. The entire layer willeventually decompose into the ground, thereby providing a non-harmfulmethod of disposing of the almond wood chips.

It should be noted that the agriculture growth control device of thepresent invention is not limited to the above configuration. In fact,the device of the present invention can be individually tailored for avariety of different applications. For example, collar 8 a may comprisea number of separable portions 20, 22 (see FIG. 4A) to facilitate theplacement of collar 8 a around larger vegetation, such as a tree orlarge bush. In this configuration, collar 8 a may have a variety ofshapes other than circular, as is illustrated by the rectangular shapein FIG. 4A. In addition, sheet 4 b may include a relief 24 underlying asolid portion 26 of organic layer 6 b, as shown in FIG. 4B. A seed 28 isplaced within the relief 24 so that a plant can grow through layer 6 b.Alternatively, collar 8 c may comprise a number of holes 10 c for aplurality of plants, such as a vegetable or flower garden (shown bottomside up in FIG. 4C).

The method for constructing collar 8 will now be described withreference to FIG. 3. The impermeable sheet 4 (shown in FIG. 2) is formedby grinding a paper material, such as newspaper, into water to form afiber slurry 50. Preferably, fiber slurry 50 will initially compriseless than 20% by volume of paper material and more preferably about 5%by volume of paper material (i.e., 95% by volume of water). The fiberslurry 50 is then poured onto an endless belt 52 having a number ofsmall openings (not shown) to allow some of the water to immediatelydrain from fiber slurry 50. The slurry is pressed by a roller 54 toremove another portion, preferably about 60 to 80%, of the water fromslurry 50 to form a partially solidified layer 56. In addition, suctionpressure may be applied to the underside of belt 52 with, for example, avacuum 58, to facilitate the removal of the water.

A second slurry 60 is then introduced onto the top of solidified layer56 through a mixer 62. Second slurry 60 preferably comprises a mixtureof about 5-95% by volume of a biodegradable, organic material, such asalmond wood chips, and 5-95% by volume of water. Since layer 56 issubstantially more solidified than second slurry 60, the second slurrywill generally rest on top of layer 56. The newspaper helps the slurry60 stick to the top of layer 56. At this point, first and secondslurries 50, 60 are delivered through a vacuum press 64. Vacuum press 64removes water by suction and by pressing the slurries between press 64and belt 52.

Other materials, such as seeds, chemical fertilizer or soil nutrientsmay be added during the manufacturing process. In the preferredembodiment, the additional materials will form a part of the initialfiber slurry 50 that is introduced onto belt 52. However, thesematerials may be added with the second slurry 60 or, they may be addedbefore slurry 60 has been introduced (as fiber slurry 50 is slowlybecoming solidified). Of course, the materials may also be imbedded intothe fiber mat 4 after collar 8 has been completely solidified (discussedbelow).

After a substantial portion of the water has been removed from slurries50, 60 (preferably about 80 to 90%), belt 52 moves the mixture into anenclosed housing 66. Within this housing 66, the slurries are pressedbetween a draper chain 68 and belt 52. In addition, slurries 50, 60 areheated by a heater 70 to further solidify and dry the mixture. The finalsemi-rigid product 72 then exits housing 66 and is cut into variousshapes and sizes depending on the application, as discussed above. Forexample, hole 10 may be drilled through collar 8 and concave uppersurface 12 may be formed by conventional techniques, e.g., contouringthe ground surface. Alternatively, the semi-rigid product 72 may beformed into a large roll as it is discharged from belt 52, instead ofcutting the binder into discrete sizes and shapes. The roll can be used,for example, on large farms for planting a crop through the roll.

The fiber and the organic material, e.g., almond wood chips, are choppedinto fine pieces by a chip cutter before they are mixed with the waterto form the slurries. FIGS. 5-9 illustrate the preferred embodiment of achip cutter 80 according to the present invention. As shown in FIGS. 5and 7, chip cutter 80 includes an outer base assembly 82 that is made upof a plurality of threaded rods 85 extending through circumferentiallyspaced holes 86 in a number of annular spacer disks 88. A number ofpipes 84 are placed over the threaded rods 85 between holes 86 in disks88 in a sequential manner. Pipes 84 are also preferably held to a driveassembly 106 on each end of outer assembly 82 with a conventional washer91. As shown in FIG. 6, drive assemblies 106 are connected to an axialshaft 102 through an end plate 103 with bolts extending through holes103 a in end plate 103 and tapped holes 102 a in drive assembly 106.

A plurality of cutting blade assemblies 90 are slidably and rotatablycoupled to pipes 84. As best shown in FIGS. 8 and 9, cutting bladeassemblies 90 each include a blade 92 mounted to a hollow tube 94 via amounting bracket 96 so that blade 92 is spaced from tube 94. This allowsblade 92 to rotate relative to outer assembly 82, as discussed below.Blade 92 is preferably constructed of metal, such as high speed steel,and includes a base portion 93 and a sharpened tip 95 facing oppositetube 94. Mounting bracket 96 is bonded, e.g., welded, to the outersurface of tube 94 and is preferably angled such that blade 92 extendsin a substantially radial direction relative to tube 94. Mountingbracket 96 and blade 92 each include a pair of holes 98 for receivingbolts 100 for connecting blade 92 to bracket 96. Of course, theinvention is not limited to this configuration and blade 92 may bemounted to tube 94 in a variety of conventional manners.

Referring again to FIGS. 5 and 7, tubes 94 are disposed around pipes 84between spacer disks 88 so that cutting blade assemblies 90 are slidablyand rotatably disposed about pipes 84. In this manner, blades 92 willrotate slightly relative to base assembly 82 when base assembly 82 isrotated around the axis of shaft 102. This provides flexibility toblades 92 during the cutting of chips, paper products, etc., asdiscussed below. The diameter of tubes 94 will be close enough to theouter diameter of pipes 84 such that rotation of base assembly 82 willeffect a rotation of cutting blade assemblies 90. In the preferredembodiment, chip cutter 80 will include between 5-100 cutting bladeassemblies and more preferably about 50 cutting blade assemblies,extending circumferentially around the longitudinal axis of outerassembly 82 (see FIG. 7). Tubes 94 extend beyond mounting bracket 96 andcutting blades 92 to permit contact of tubes 94 against disc 88 whilerotating around pipes 84. Cutting blade assemblies 90 are mounted onalternating pipes 84 to allow room for each blade 92 to rotate withoutcontacting an adjacent blade 92. Preferably, about 1-24 cutting bladeassemblies 90 will be disposed along each rod 25 (i.e., in thelongitudinal direction, see FIG. 5).

It should be noted that the present invention is not limited to theabove configuration for spacing cutting blade assemblies 90 from eachother. For example, the blade assemblies may alternate in both thelongitudinal and circumferential direction. In this configuration, allof the cutting assemblies would be disposed on pipes. However, theywould alternate so that a cutting assembly will be disposed on everyother pipe in the circumferential direction and offset between everyother spacer disk in the longitudinal direction.

As shown in FIGS. 5 and 6, axle shaft 102 is coupled to a motor shaft(not shown) via a multiple belt pulley 104 for rotating base assembly 82and cutting blades 92 therewith around the shaft axis 102. A seconddrive assembly 83 is mounted on the opposite end of outer assembly 82.In the preferred embodiment, outer assembly 82 includes a wheel hub 106coupled to an axle 108 by a pair of roller bearings 110. Axle 108 is, inturn, coupled to axle shaft 102 by an outer support bearing 112. Theaxle, axle shaft and wheel hub can be specifically manufactured for chipcutter 80 or, alternatively, these pieces can be removed from a suitableexisting axle, such as the rear drive axle of trucks.

To cut the fiber and almond wood chips, a motor (not shown) is energizedso that multiple belt pulley 104 rotates axle shaft 102 at a suitablespeed, preferably between 2000 to 4000 RPM. Axle shaft 102 rotates baseassembly 82 and cutting blade assemblies 90 about the axis of shaft 102.The fiber and almond wood chips are then fed into assembly 82 so thatblades 92 chop them into fine pieces.

Although the foregoing invention has been described in detail forpurposes of clarity of understanding, it will be obvious that certainmodifications may be practiced within the scope of the appended claims.For example, flour or vegetable starch can be added to the second slurryto facilitate the binding of the two slurries together. Alternatively, afire retardant, such as clay, can be used as a binding agent. In thisconfiguration, the collar would be additionally useful as a firebreakbetween fields.

What is claimed is:
 1. A cutting device comprising: a base assembly comprising first and second ends and a longitudinal axis therebetween, the assembly defining an outer portion rotatable about the longitudinal axis; a plurality of cutting assemblies circumferentially disposed around the outer portion of a housing and spaced from each other, each cutting assembly comprising a mount coupled to the outer portion of the base assembly and a blade extending outwardly from the mount; an elongate shaft coupled to at least one of the ends of the base assembly for rotating at least the outer portion of the assembly, and the cutting blades therewith, about the longitudinal axis wherein the blades each have a sharp edge extending substantially parallel to the longitudinal axis; the outer portion of the base assembly comprises a plurality of rods with pipes extending substantially parallel to and circumferentially spaced around the longitudinal axis; and, the mounts of the cutting assemblies comprise hollow tubular members having an inner radius greater than an outer radius of the pipes, the tubular members being rotatably disposed on the pipes such that the cutting assemblies are rotatable with respect to the base assembly.
 2. The cutting device of claim 1 wherein each rod rotatably supports a number of the cutting assemblies to form rows of cutting assemblies around the longitudinal axis of the base assembly.
 3. The cutting device of claim 2 wherein the base assembly further comprises a plurality of annular spacer disks each having multiple holes for receiving the rods, the pipes being place over the rods and between the spacer disks, the tubular members of the cutting assemblies being slidably disposed along the pipes between adjacent spacer disks.
 4. The cutting device of claim 3 wherein the rows of cutting assemblies are formed on alternating pipes to minimize contact between adjacent cutting blades.
 5. The cutting device of claim 3 wherein the annular spacer disks each define a central hole, the device further comprising an axle and a hub extending through the central holes in the spacer disks and a multiple belt pulley for coupling the axle shaft to a motor for rotation of the axle shaft. 